Method of setting up apparatus for handling electrical or electronic components

Abstract

A setting-up plate is mounted on an X-Y table of a component placement machine. The plate has an array of fiducial marks thereon whose positions are accurately known. A control system drives the table by an amount which should bring each mark in turn to a reference point of a detecting device. The detecting device detects the actual position of the mark relative to the reference point. Errors in the table drive are thereby detected and can be allowed for.

We claim: 
     
       1. A method of setting up a component placement machine comprising a pick-up head having a pick-up tool, an X-Y table on which substrates on which components are to be placed may be mounted, and a control system for the X-Y table comprising the steps of: (a) mounting a setting-up plate, provided with an array of fiducial marks having accurately known X-T coordinates relative to the plate, in an accurately known position on the X-T table by means of aligning location points of the X-Y table and the setting up plate,   (b) inputting into the control system said known X-Y coordinates of said fiducial marks in the array,   (c) causing said control system to sequentially locate each fiducial mark at a known position,   (d) locating a camera having a field of view defined by an X-Y array of pixels so that the X-Y array of pixels is oriented to correspond to the X-Y array of fiducial marks and so that a selected pixel will see said know position,   (e) for each fiducial mark located at said known position, determine the actual pixel which locates said fiducial mark and determine the number of pixels in the X line of pixels and in the Y line of pixels required to relocated that pixel to said selected pixel, and   (f) defining based on such number of pixels, X-Y corrections for said control system when locating the X-Y table.   
     
     
       2. A method according to claim 1 wherein the camera is a charge coupled device camera.